Power supply failure and other problems

I've experienced what seems to be a combination of problems reported by others with this monitor unit:
For the past year, occasionally I've see a "faded" patch of pixels at the top of the screen, near the center. Often this seemed to happen when a sold color was displayed in the area continuously (for example, during the Olympics soccer matches, when the green grass was continuously displayed in that area). Or it would appear where there might be a shiny patch on somebody's forehead. Turning off the monitor for awhile would alway help the problem go away. But I hadn't noticed this symptom recently...
Just yesterday, I experienced a complete failure of the power supply. This occurred when turning the system on - mading a pretty loud POP. I've taken a look inside and see that a 0.1 ohm resistor (R133) blew. Also a 0.47 ohm resistor adjacent to Q127 and it's heat sink is toasted .
I've tried testing the power connections to the large right (X DRIVE ASS'Y) and left (no obvious name) boards, but don't measure shorts - but maybe I'm not testing the right pins.
I'm planning to replace the blown resistors, but am afraid there is a deeper problem which caused the failure in the first place. Any suggestions on more detailed analysis I can do to determine the root cause would be greatly appreciated!

Anonymous

Re: Power supply failure and other problems

Where do you live. In new jersey? I maybe able to help you directly as I am an engineer like yourself. Usually low value resistors are the first to go because they cannot handle a power increase by much. This usually occurs because a power transistor is shorted causing more current flow to the biasing resistors. Is this problem on the main screen or the control box. Email me at tinujatinpatel@gmail.com

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Common problems on monitors are due to capacitors in the power supply/inverter circuits failed, you need to open it up and look inside for caps with bulging top/seal first and post back what you see so we can guide you further, see failed monitors due to bad caps: http://s807.photobucket.com/home/budm/allalbums

Did you try feeding the audio line input jack with an MP3 (using MP3 headphone audio out) to find out if you do get sound? The volume control panel shows on the screen when you hit the Volume up/down buttons? Otherwise you may have power amplifier failure inside the unit ot it may lose the power supply feeding the amplifier.

they can be repaired by an electronic tech but are cheaper buying a new one. The cost of new inverters range from 30-80$ USD. Viewsonics don't cost that much and now you can get 18.5 inch widw screen acer or other brand lcds for 89$.

jefkare, If unit is still covered by warranty LG (Lucky Goldstar) should replace it! Sure seems like a "switch-mode-power-supply" failure to me. try using unit at a KNOWN GOOD pc to see if problem moves with the monitor. Next, prove that different monitor functions perfectly with your PC. Try reinstalling drivers for LG L227 maybe that will work. Also try setting the screen resolution to a lower setting. Good luck guy. Do a reply if in need of further assistance. Bye for now. 12fixlouie on fixya.

This problem sounds like a failure of the monitor power supply switching transistors breaking down under load conditions.This unit needs to be taken to a service center for repair. It also could be other intermittent components affecting the power supplied to the monitor. Hope this helps.

Have you recently experienced a power surge or had an electrical (thunder) storm in your area? Potentially your motherboard and/or processor could be toast since the fan running and CD Rom drive opening will continue to function because they receive power separately from the motherboard via the power supply. If you have access to a different compatible processor, you could try to install it in the motherboard to rule out a motherboard failure, otherwise you're looking for a new motherboard.

As for which one has the problem, I would say it has to be the battery. Rechargeable batteries of all types are known to have similar characteristics, one of which is discharging the batteries to maintain good rechargeablility.
At least one person has demonstrated this for the Scooba battery in the roombareview.com forums when he brought a "dead" battery back to life. He allowed the battery to slowly and completely discharge using a 12-volt automobile bulb, followed by recharging the battery on the Scooba external charger.
This procedure brought his "dead" battery back to a full charge!
However, other forum members have reported that many have experienced problems with Scooba battery life, and that as a consequence of this iRobot will replace your battery if you call them and report a short-life battery problem.
You can contact iRobot at (800) 727-9077 if you would like to report a battery problem and request a replacement.